Clamp



Qct. 13, 1942.

R. R. HARRISON CLAMP Filed Dec. 20, 1941 INVENTOR. ROBERT R. HARRISONATTORAEX Patented Oct. 13, 1942 CLAMP Robert R. Harrison, NorthHollywood, Calif., as-

signor to Bendix Aviation Corporation, South Bend, Ind., a corporationof Delaware Application December 20, 1941, Serial No. 423,844

1 Claim.

This invention relates to clamps for supporting elongated objects, andrelate more particularly to a cushioned clamp adapted to support wiresgrouped in bundles or cables.

In the past it has been common practice in electrical work to grouptogether numerous wires, and place them within a protecting conduit. Forexample, in airplane work radio wires in the past have been tiedtogether in cables and then inserted in a conduit of solid or wovenmetal. Such conduits have added unnecessary weight, and have hinderedthe repair f wires when they were broken, as by gunfire in militaryairplanes. The present tendency, therefore, is toomit conduits fromairplane wire cables.

In the past with wire cables having metal conduits protecting them, ithas been common practice to use clamps of bare metal to secure the wirecables in position. With the elimination of metal conduits, however,clamps must be used which are provided with a cushion so as to protectthe wire forming the cables from the metal forming the clamp. Thiscushion is preferably an insulator such as rubber or a synthetic rubbersuch as neoprene or other rubber-like materials.

Several types of clamps are available on the market having a cushionelement which would protect wires from contact with the metal formingthe clamp. One such type of cushion is that in the form of a tubethrough which a metal strip is inserted, the tube being stretched ovrrthe metal strip. Such a cushion would completely protect the wires frominjury. Another available type of cushion for clamps is one wherein thecushion is formed in the shape of a channel with inturned edges so thata cushionmay be snapped on to a metal strip. Both types of cushions areshown in my co-pending application Serial Number 387,210.

The present invention relates to a clamp particularly designed forholding cables of wires. Its basic structure comprises a strip of metalbent to form a loop, and having sheet cushion material vulcanized orbonded to the inside of the loop. The forming of the cushion from sheetmaterial is much cheaper than cushions formed from tube or channelsections as have been described. Further, clamps made according to thepresent invention can be made much more easily and quickly by using asheet material cushion rather than a tubular cushion. In the presentinvention the sheet material extends beyond the edge of the metal clampso as to adequately shield any wires from the metal of the clamp in anypossible condition of service or assembly of the wires.

It is therefore an object of the invention to provide an inexpensive andeasily manufactured cushioned clamp particularly adapted for use withwire cables.

Another object of the invention is to provide a metal clamp having acushion of sheet material wherein the cushion projects a substantialamount beyond the edges of the metal forming the clamp.

Another object is to provide a clamp in which is formed inexpensive andvery useful nut means for holding a screw which may be used to securethe clamp to a support.

Other objects and advantages of the invention will be apparent in thefollowing description taken in connection with the following drawinginwhich:

Figure 1 is an isometric view of a section of a structural member in anairplane to which are secured two clamps made in' accordance with theinvention each of which holds a wire cable;

Figure 2 is an elevation view of the upper clamp of Figure 1 showing theshape of the cushion element and showing nut m'eansformed in the metalof the clamp;

Figure 3 is an elevation view partial in section along the lines 3-'3 ofthe lower clamp of Figure 1 showing a different nut means integrallyformed therein; and

Figure 4 is an elevation view of a clamp made according to theinvention, having a circular opening therein and. having nut meansapplied to the clamp by placing over the clamp a separate piece of metalwith a nut formed therein.

Referring to Figure 1, mounted on an airplane structural member 8 is aclamp l0 having a cushion l2 and supportin a wire cable l4. Secured tostructural member 8 is a second clamp l6 having a cushion l8 andsupporting a wire cable 20.

I0 is secured to structuralmember 8 by a screw 9 inserted from the backof structural member 8 and passing therethrough to contact raisedfingers I I comprising nut means in the clamp II) which act as a nut.The lower clamp 16 is secured to the member 8 by screw I! inserted fromthe face of member 8 through it to contact nut means, which will belater described, on the clamp IS.

The upper clamp I0 is shown in more detail in Figure 2. There it will benoted that the cushion element I2 is not bonded to the clamp l0throughout its length, but rather has a free flap l3 which hinges at thefar end of the clamp I0 and reaches nearly to the other end of the clampIt will be noted that the upper clamp forming a'complete enclosuretherein. The nut means I l are also shown in Figure 2 and a screw passedthrough the clamp at this point will be engaged by nut means H to hold.the clamp to- ,cushion any wire cables from the support member 8 towhich the clamp is secured. As shown in Figure 1, the clamp is has anear it which passes around to the back of structural member 8 and hasnut means formed therein as shown in Figure 3. The nut means comprisesan extrusion 29 formed in ear 65 by merelypiercing the original sheetmetal of ear E5. The screw ll holding the ear l5 to the support 8 is ofthe self-threading type, and cuts its own threads into extrusion 28 whenit is screwed therein.

The clamp shown in Figure 4 is an alternative type wherein it is desiredto maintain the wire cable or other held element in a substantiallycircular form. A clamp 30 has bonded or vulcanized thereto a cushion 32of rubber-like material having a free flap 33 to complete the enclosureof the clamp. Placed over the flat end of clamp 36 is a U shaped metalmember 34 having nut means 35 formed therein, these nut means beingplaced over a hole 36 in the flat end of clamp 30. This type ofstructure permits the use of aluminum or other soft materials in makingthe clamp 30, while maintaining the quality of the nut means 35 byhaving the small piece of metal 36 made of steel or other hard metalwhich will form a high quality nut.

it is therefore necessary to provide protection from the metal. Thecushion elements are most easily applied to their respective clamps bybonding them thereto when the metal is in the flat strip form. After thebonding is complete the metal of the clamp may be bent into any desiredshape and will thereafter be ready for use. The fabrication of thecushions from sheet material permits the use of cushion stock materialin its cheapest, form, that of sheets.

Although this invention has been described with reference to particularembodiments thereof, it is not limited to these embodiments norotherwise except by terms of the following claim.

I claim:

Means for securing a bundle of wires to a support comprising -asubstantially semi-circular loop having a flange-like extension at oneend for attachment to a support, the other nd being free, and a cushionof flat material bonded to the inner face of the loop and having aportion extending beyond the free end of the loop adapted to be disposedbetween the bundle of wires and the support.

ROBERT R. HARRISON.

